Background: Hypertension is common in chronic hemodialysis patients, yet there are limited data on the epidemiology of hypertension in these patients in the United States. Methods: We assessed the prevalence, treatment, and control of hypertension in a cohort of 2535 clinically stable, adult hemodialysis patients who participated in a multicenter study of the safety and tolerability of an intravenous iron preparation. Hypertension was defined as an average predialysis systolic blood pressure >150 mm Hg or diastolic blood pressure >85 mm Hg, or the use of antihypertensive medications. Results: Hypertension was documented in 86% (n = 2173) of patients. The prevalence of hypertension, in contrast to that observed in the general population, did not increase linearly with age and was not affected by sex or ethnicity. Hypertension was controlled adequately in only 30% (n = 659) of the hypertensive patients. In the remaining patients, hypertension was either untreated (12% [252/2173]) or treated inadequately (58% [1262/2173]). Conclusion: Control of hypertension, particularly systolic hypertension, in chronic hemodialysis patients in the United States is inadequate, despite recognition of its prevalence and the frequent use of antihypertensive drugs. Optimizing the use of medications and closer attention to nonpharmacologic interventions, such as adjustment of dry weight, a low-sodium diet, and exercise, may improve control. © 2003 by Excerpta Medica Inc.